Four straight days of rain have replenished several key reservoirs in Northern California, delighting a state in its fifth year of drought and raising hopes that water-use restrictions might be eased.

The series of storms that started late last week drenched the state, closing roads and schools while causing flooding and power outages.

Northern California was the hardest hit over four days. Other parts of the state saw the heaviest rainfall late last week.

Forecasters had issued an avalanche warning that expired Monday along the crest of the Sierra Nevada, where the highest peaks received up to 150 cm of snow over the weekend. The snowpack normally stores about 30 per cent of the state's water supply.

As the latest storm weakened, warm temperatures and blue skies were forecast throughout California during the rest of the week.

Full reservoirs and lush snowpack in Northern California are critical for the entire state as the water eventually flows to the agriculture rich Central Valley and densely populated Southern California, which has seen relatively little rain this winter.

Some reservoir still far below capacity

In Northern California, officials reported that lakes Shasta and Oroville haven't been as full since 2013.

Lake Shasta, the state's largest reservoir, was at 79 per cent capacity and at 103 per cent of its historical average for this time of year.

The 34-km long reservoir north of Redding now holds 3.6 million acre-feet of water, enough to supply 3 million to 6 million households for a year.

California Storms

This combo of two photos shows the cracked-dry bed of the Almaden Reservoir on Feb. 7, 2014, and the same reservoir full of water on March 14, 2016. (Marcio Jose Sanchez/AP)

"It's definitely welcome news, but it's kind of a mixed bag for us," said Shane Hunt, a spokesman for the U.S. Bureau of Reclamation. "We still don't have water in all the right places to meet demand going into peak season."

For example, man-made Lake Melones in the Sierra Nevada foothills remains at just 22 per cent of capacity and well below the historical average.

The state's second largest reservoir, Lake Oroville, was at 70 per cent of capacity and 97 per cent of its historical average. Folsom Lake, 25 miles northeast of Sacramento, was at 69 per cent of capacity.

Officials consider lifting water use restrictions

Gov. Jerry Brown ordered mandatory cutbacks of 25 per cent in water use last year. George Kostyrko, spokesman for the State Water Resources Control Board, said the panel will reconsider restrictions in May.

California Storm

The cracked-dry bed of the Almaden Reservoir is seen in San Jose, Calif., on Feb. 7, 2014. (Marcio Jose Sanchez/AP)

"March is really looking good so far and we're hoping for an awesome April, but we can't revisit our regulations until the end of the water year, which is April," he said.

Two people in Northern California died earlier this month in previous storms. One woman drowned after the car she was riding in drove into floodwaters in the Sacramento area. Another person was killed in the San Francisco Bay Area when a car jumped a roadway and hit trees.